Shokushu Byoutou [-666-]

The main character is a young girl. From the outside she appears to be normal, but she has an unfortunate disease which causes her excrement to turn into tentacles within her own body. Every day they attack her driving her to the brink of madness... she finally can't take it anymore and throws them off of her and into the road where she beats them until they stop moving. At that time her condition is discovered and she is put in to a "care ward." Contained in room 666, the tentacles being to overrun her body, making her scream and moan in pain. As she daily gives birth to them from her anus they continue their relentless violation. As she completely loses her sense, she starts to believe that the tentacles are really a part of her body. What is the the sad fate of this unwilling captive?